<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <!-- <style>
        button {
          background-color: red; 
          font-size: 24px;
        }
      </style> -->
      <!-- 加载外部样式表 -->
  <link rel="stylesheet" href="./css/07-css引入.css">
</head>
<body>
    <!-- <button style="background-color: red; font-size: 24px;">行内样式</button> -->
    <!-- <button>测试内部样式表</button> -->
    <button>测试外部样式表</button>
</body>
</html>